The biggest maker of medical face masks in the U.S. is warning consumers that the surge in demand for masks during the COVID-19 pandemic has led to a flurry of criminal activity.

Prestige Ameritech, a privately held company based near Dallas, says its name is being used in scams that include fake websites and email addresses with swindlers posing as the company or its employees.

The only URLs that can be trusted, according to Prestige Ameritech, are these: prestigeameritech.com, prestigeam.com, progearmasks.com and progearhealth.com.

“Any other website that contains the name ‘Prestige Ameritech’ or ‘ProGear Health’ is fake and needs to be reported to us,” reads a warning on the Prestige Ameritech site’s home page.

A further note of caution: Masks listed as made by Prestige Ameritech that are available on websites including eBay /zigman2/quotes/204653455/compositeEBAY-1.09%
and Amazon /zigman2/quotes/210331248/compositeAMZN+0.91%
“are most likely very old masks that have been discontinued.”

N95 masks are tighter-fitting than surgical masks and protect against small particles and large droplets, according to the Centers for Disease Control and Prevention. The company makes N95 masks under the ProGear brand that are approved by the Food and Drug Administration for protecting medical workers from the transfer of microorganisms and airborne particulate materials.

To keep up with demand, the company’s management team is working 80-hour weeks, it has brought idled equipment back on line, and is hiring and training dozens of new employees to expand its staff of around 100, Wired reported.

The company’s co-owner and executive vice president, Mike Bowen, reportedly told the magazine that the company is producing up to 1 million masks a day, up from about 250,00 a day before the ongoing coronavirus outbreak.

The requests are coming from hospitals, doctor’s office, and medical distributors, as well as from elderly people and the parents of children with compromised immune systems, anxious for protection from the illness.

“Since Feb. 1, we’ve had to turn down orders for 100 million masks or more a day, on average,” Bowen said, according to Wired. “Sometimes, we turn down 200 million or 300 million [masks] a day. It’s kind of surreal.”

Prestige Ameritech is not the only one boosting production of face masks. Dow Jones Industrial Average /zigman2/quotes/210598065/realtimeDJIA+3.15%
component 3M Co. /zigman2/quotes/205029460/compositeMMM+2.99%
has been increasing its production in recent months, initially in response to high demand from China, which reported the first cases of COVID-19 late last year. On the company’s fourth-quarter earnings call in January, Chief Executive Mike Roman said demand in China had spiked as more cases emerged.

“Now, coronavirus, it’s kind of changing things as we go, and we’re seeing what you’re seeing,” Roman said in 3M’s post-earnings-report call, according to a transcript provided by FactSet. “We’re seeing increased demand for our respiratory protection products, and we’re ramping up our production worldwide ... to meet that demand.”

In March, Vice President Mike Pence said the U.S. government had contracted with 3M for the manufacture of 35 million more masks a month in response to the virus.

The government and agencies including the Centers for Disease Control and Prevention, the U.S. Department of Health and Human Services, and the U.S. surgeon general have told Americans not to buy face masks, which are not effective in containing the virus but are crucial for health-care providers coming in close contact with patients.

On Wednesday, Pence said the government is stepping up its push for more masks for health-care workers. A day earlier, Pence had asked construction companies to donate their inventories of N95 face masks to local hospitals and to stop ordering new ones.

Coronavirus Boosts Some Medical-Supply Makers' Shares

Long lines at pharmacies and soaring demand for respiratory masks and plastic gloves show how the coronavirus outbreak has benefited some companies. WSJ explains why some medical supply stocks have skyrocketed—and whether it can last. Photo: Kin Cheung/Associated Press

This COVID-19 pandemic era is not the first time Prestige Ameritech has faced a sudden surge in demand for its products. The company faced a similar rush during the H1N1 outbreak in 2009 and hired hundreds of additional workers to cope. But as soon as that outbreak was over, its U.S. customers shifted back to Chinese suppliers, who can produce protective equipment at a fraction of the company’s costs, according to Wired.

3M shares have fallen 36% in the last 12 months, while the ProShares Ultra Industrials ETF /zigman2/quotes/201293807/compositeUXI+7.27%
has fallen 51% and the S&P 500 /zigman2/quotes/210599714/realtimeSPX+2.62%
has fallen 16%.

Intraday Data provided by FACTSET and subject to terms of use. Historical and current end-of-day data provided by FACTSET. All quotes are in local exchange time. Real-time last sale data for U.S. stock quotes reflect trades reported through Nasdaq only. Intraday data delayed at least 15 minutes or per exchange requirements.